The invention relates to a method for cooling flat plastic products, in which plasticized plastic compound is fed to a calender via a slot nozzle by means of an extruder and is rolled and calibrated to the desired shape in this calender between at least two smoothing rolls, after which the film or sheet produced in this way is fed to a chill section comprising a plurality of adjustable rolls and passes through this section until it is sufficiently cool and dimensionally stable, at least both the gap width between the rolls and the speed of the rolls being controllable by open- and/or closed-loop control.
Calenders of this kind are known from the prior art. For this purpose, EP 1 600 277 A2 describes an apparatus for calibrating and cooling a plastic film or plastic sheet comprising at least two chill or calibrating rolls, a chill section being arranged downstream of the rolls. According to the invention, the downstream chill section comprises pairs of rolls arranged one behind the other.
In chill sections of this kind, it is true that the position of the rolls can be adjusted, thereby allowing the cooling capacity to be influenced. However, it has been found that, as the rolls are adjusted, the film passing through partially loses contact with the roll, thereby giving rise to differences in the cooling behavior of the film.